n--C1 to C4 -alkyl-5-bromo-ortho-cresotamides; their use as anticonvulsants. 5-Bromo-ortho-cresotamide may also be named 5-Bromo-2-hydroxy-3-methyl-benzamide.
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3. A method of reducing convulsions in a host which comprises administering to the host an anticonvulsant amount of an n--C1 to C4 -alkyl-5-bromo-ortho-cresotamide.
1. A composition useful as an anticonvulsant which comprises an anticonvulsant amount of an n--C1 to C4 -alkyl-5-bromo-ortho-cresotamide in a pharmaceutically acceptable diluent.
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This is a continuation of application Ser. No. 264,501, filed June 20, 1972.
The present invention relates to a series of derivatives having psychotropic activities which are derived from cresotic acid.
These new drugs have the overall formula: ##SPC1##
R may be a hydrogen, a straight or branched-chain lower alkyl radical, an alkenyl radical, an ethinyl radical, or an esterifying acid radical, namely acyl, thenoyl, halothenoyl or benzoyl.
R' may be an --OH, --OCH3, --O-alkyl, O-alkenyl, O-ethinyl, --NH2, straight or branched-chain N--dialkyl, --NH-alkyl, NR"--A--N-dialkyl, --O--A--N-dialkyl, NR"--A--N-morpholino, or --N-cycloalkyl radical.
A may be a straight or branched alkyl chain of 2 to 5 carbon atoms, which chain may be unsaturated.
R" may be a hydrogen or a lower alkyl.
Finally, the nitrogen atom may be included in a ring to form a piperidino, pyrrolidono, morpholino or piperazino group, for example: ##EQU1## X may be a hydrogen, halogen or an NO2 radical. N MAY BE EQUAL TO 0, 1 OR 2.
The position of the CH3 radical on the ring may vary.
The invention also relates to therapeutically acceptable salts of derivatives having an amine function.
These derivatives may be obtained by different methods, namely:
PAC (Aminolysis of the Corresponding Methyl Ester)Principle: ##SPC2##
To 1 mol of Product A 1.5 mol of the corresponding amine is added. When the amine is gaseous it is used in alcoholic solution and the reaction can be carried out in an autoclave.
When the amine is crystalline, a solvent is employed; on the other hand, when it is liquid, we did not employ a solvent.
The reaction mixture is set aside for several hours at room temperature and then heated for a few hours at 90°C. The solvent, if any, is distilled and the products are recovered by the customary techniques, namely:
Distillation under reduced pressure, or
Crystallization of the amide.
In the case of diamines, the products can be recovered in the form of hydrochloride.
PAC Preparation of methyl 5-bromo 2-hydroxy 3-methyl benzoateAdd 300 g of cresotic acid to a solution of 90 g of sulfuric acid in anhydrous methanol; heat for 30 hours; the solution becomes dark red. Expel the methanol, dissolve the residue in chloroform and pour into ice water; the original cresotic acid crystallizes and can be removed. The chloroform phase is washed with a bicarbonate solution in water, dried over Na2 SO4 and concentrated and the residue distilled. (b.p.15 = 104°- 105°C). Methyl 2-hydroxy 3-methyl benzoate is obtained; the yield is 77%. The index of refraction nD25 is equal to 1.5322.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether (5:95)
Rf : 0.72.
The methyl 2-hydroxy 3-methyl benzoate in solution in the dioxane is added, drop by drop, to a chloroform solution of bromine maintained at 0°C. Excess bromine can be used since only one position is capable of bromination in the event that the methyl group is in 3 position.
Then set aside for several hours under nitrogen, recover the chloroform phase, wash with a bicarbonate solution and then with water, concentrate, and crystallize.
This product is obtained in the form of fine white needles.
Melting point: 107°C.
Soluble in dimethyl formamide, dimethyl acetamide, methyl pyrrolidone, ether, and chlorinated solvents.
Add 900 cc of 20% ammonia to 49 g of methyl 5-bromo 2-hydroxy 3-methyl benzoate in 2 liters of ethanol at 95°C. Set aside for 72 hours at room temperature, with agitation; cool with ice, add 300 cc of hydrochloric acid (6N), and then extract with ether; finally concentrate and crystallize by addition of petroleum ether; 29 g of 5-bromo 2-hydroxy 3-methyl benzamide are obtained (yield: 63%).
The product is in the form of white crystals; it is soluble in alcohol, methyl pyrrolidone, propylene glycol and ether; it is insoluble in water and petroleum ether.
Melting point: 173°C.
Plate Chromatography:
Support: Kiesel Gel F 254
Solvent: ethyl acetate/petroleum ether (50:50)
Rf : 0.46 ##SPC3##
Another example:
1. Dissolve 956 g of ortho-cresotic acid in 4 liters of acetone. Add 567 g of NaHCO3 and then add thereto 835 g of dimethyl sulfate. After refluxing for 5 hours, cool, filter off the salt which has formed, and concentrate to dryness. Subject the crude ester thus obtained to distillation under vacuum (b.p.: 100°C at 5 mm Hg). 944 g of methyl ester (I) are obtained (yield 90%).
2. Dissolve the 944 g of ester (I) in about 6 liters of chloroform. Add a solution of 907 g of bromine in about 1.8 liters of chloroform. After the addition, which requires several hours, reflux the reaction medium for 2 hours and then concentrate the solution until the appearance of crystals of bromo-ester. Cool and allow to crystallize, centrifuge and dry the crystals in a stove under vacuum. In this way there are obtained 1250 g of methyl p-bromo-orthocresotate (II) (yield 90%).
Melting point: 109°C.
Thin-layer chromatography: a single spot.
3. Saturate 3.7 liters of absolute methanol with 750 g of ammonia and add the above 1250 g of bromo-ester.
Heat and maintain the temperature at 50°-60°C for 3 hours.
The maximum pressure recorded within the autoclave is about 6 kg/cm2. After elimination of the excess ammonia under vacuum, concentrate to dryness, wash the solid with water, and recrystallize from 25 liters of benzene.
1 kg of pure p-bromo-ortho-cresotamide is obtained. (yield of the amidation: 85%).
PAC (Reaction of Acetylated Acid Chloride on the Corresponding Amine)Basic reaction: ##SPC4##
The intermediate acetyl derivatives can be isolated or saponified to lead directly to the amides desired.
1 mol of acid chloride (Product C) is added in separate portions to a chloroform solution of an amine mol.
The reaction mixture is refluxed for several hours; the solvent is distilled.
The residual product is recovered by the customary techniques.
The deacetylation is effected by treating Product D with a 1N aqueous soda solution.
The following derivatives have been obtained by Method A as intermediates capable of undergoing further aminolysis:
Methyl 5-chloro-ortho-cresotate
(R' = OCH3, X = Cl)
Overall formula: C9 H9 Cl NO3
White crystals -- melting point: 62°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 35:60
Rf : 0.48 (U.V. development)
Insoluble in water and propylene glycol;
2% soluble in ethanol and 8% soluble in DMF.
Methyl 5-iodo-ortho-cresotate
(R' = OCH3, X = I)
Overall formula: C9 H9 IO3
White crystals -- melting point: 97°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 35:60
Rf : 0.51 (U.V. development)
Insoluble in water and propylene glycol;
2% soluble in ethanol and 10% soluble in DMF.
Methyl 5-nitro-ortho-cresotate
(R' = OCH3, X = NO2)
Overall formula: C9 H9 NO5
Yellow needles -- melting point: 126°C.
Silica plate chromatography
Solvent: petroleum ether/ethyl acetate 95:5
Rf : 0.60 (U.V. development)
Insoluble in water and propylene glycol.
Very slightly soluble in ethanol (0.5%).
By aminolysis of the methyl esters, a few examples of which have just been given, there have been obtained the following derivatives with amide function other than the 5-bromo 2-hydroxy 3-methyl benzamide described previously;
1. N(dimethyl N',N'-amino 2'-ethyl) 5-bromo-ortho-cresotamide hydrochloride: ##EQU2##
Overall formula: C12 H18 Br Cl N2 O2
White crystals -- melting point = 192°C.
Silica plate chromatography.
Solvent: Butanol/acetic acid/water 6:2:2
Rf = 0.72 (U.V. development)
Soluble in water (10%), ethanol (2%) and propylene glycol (4%).
2. N(diethyl-N',N'-amino 3'-propyl) 5-bromo-ortho-cresotamide hydrochloride: ##EQU3##
Overall formula: C15 H24 Cl Br N2 O2
White crystals -- melting point: 130°C.
Silica plate chromatography.
Solvent: butanol/acetic acid/water 6:2:2
Rf : 0.70 (U.V. development)
2% soluble in water, 8% in ethanol, and 30% in methyl pyrrolidone.
3. N(dimethyl N',N'-amino-3'-propyl) 5-bromo-ortho-cresotamide hydrochloride: ##EQU4##
Overall formula: C13 H20 Br Cl N2 O2
White crystals -- melting point: 203°C.
Silica plate chromatography.
Solvent: butanol/acetic acid/water 6:2:2
Rf : 0.66 (U.V. development)
Soluble in water, practically insoluble in ethanol.
4. N(dimethyl-N',N'-amino 2'-ethyl)5-bromo-ortho-cresotamide hydrochloride: ##EQU5##
Overall formula: C14 H22 Br Cl N2 O2
White crystals -- melting point: 132°C.
Silica plate chromatography.
Solvent: butanol/acetic acid/water 6:2:2
Rf : 0.72 (U.V. development)
Soluble in water, 6% soluble in ethanol and 9% soluble in ethylene glycol.
5. N(morpholino 3'-propyl) 5-bromo-ortho-cresotamide hydrochloride: ##EQU6##
Overall formula: C15 H22 Br Cl N2 O3
Pale yellow crystals, melting point: 174°C.
Silica plate chromatography.
Solvent: butanol/acetic acid/water 6:2:2
Rf = 0.80 (U.V. development)
0.3% soluble in water, 6% in ethanol and 7% in propylene glycol.
6. N(morpholino 2'-ethyl) 5-bromo-ortho-cresotamide hydrochloride: ##EQU7##
Overall formula: C14 H20 Br Cl N2 O3
White crystals -- melting point: 228°C.
Silica plate chromatography.
Solvent: butanol/acetic acid/water 6:2:2
Rf = 0.82 (U.V. development)
0.5% soluble in water, 0.3% in ethanol and 1% in DMF.
7. N(pyrrolidino 2'-ethyl) 5-bromo-ortho-cresotamide hydrochloride: ##EQU8##
Overall formula: C14 H20 Br Cl N2 O2
White crystals -- melting point: 184°C.
Silica plate chromatography.
Solvent: butanol/acetic acid/water 6:2:2
Rf = 0.75 (U.V. development)
10% soluble in water, 3% in ethanol, and 7% in propylene glycol.
8. 5-chloro-ortho-cresotamide:
(R' = --NH2 , R = H, X = Cl)
Overall formula: C8 H8 Cl NO2
White crystals -- melting point: 181°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 30:70
Rf = 0.55 (U.V. development)
5% soluble in ethanol, 1% in propylene glycol, 20% in dimethyl acetamide, and 15% in methyl pyrrolidone.
Insoluble in water. 9. 5-iodo-ortho-cresotamide:
(R' = --NH2 , R = H, X = I)
Overall formula: C8 H8 INO2
Beige crystals, melting point: 180°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 30:70
Rf = 0.60 (U.V. development)
Insoluble in water, 9% soluble in ethanol, 50% in dimethyl formamide, and 25% in dimethyl acetamide.
10. 5-nitro-ortho-cresotamide
(R' = NH2 , R = H, X = NO2)
Overall formula: C8 H8 O4 N2
Orangeish-white crystals -- melting point: 245°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 25:75
Rf = 0.41 (U.V. development)
20% soluble in dimethyl formamide, 6% in dimethyl acetamide, 12% in methyl pyrrolidone, and 0.5% in propylene glycol.
Insoluble in water and in ethanol.
11. N(methyl) 5-bromo-ortho-cresotamide:
(R' = NH -- CH3 , R = H, X = Br)
Overall formula: C9 H10 Br NO2
White crystals -- melting point: 162°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 30:70
Rf = 0.76 (U.V. development).
12. N(ethyl) 5-bromo-ortho-cresotamide:
(R' = NH -- C2 H5 , R = H, X = Br)
Overall formula: C10 H12 Br NO2
White crystals -- melting point: 82°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 10:90
Rf = 0.63 (U.V. development).
13. N(butyl) 5-bromo-ortho-cresotamide
(R' -- NH -- CH2 --CH2 --CH2 --CH3 , R = H, X = Br)
Overall formula: C12 H16 Br NO2
White crystals -- melting point: 76°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 5:95
Rf = 0.41 (U.V. development).
14. N(isobutyl) 5-bromo-ortho-cresotamide ##EQU9##
Overall formula: C12 H16 Br NO2
White crystals -- melting point: 67°C.
Silica plate chromatogrphy.
Solvent: ethyl acetate/petroleum ether 5:95
Rf = 0.40 (U.V. development).
15. 5-bromo-meta-cresotamide (the methyl is in 4 position):
(R' = NH2, R = H, X = Br)
Overall formula: C8 H8 Br NO2
White crystals -- melting point: 239°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 25:75
Rf = 0.39 (U.V. development)
The following derivatives, indicated by way of illlustration and not of limitation, were synthesized by Method B (reaction between acetylated acid chloride and the corresponding amine):
1. N(phenyl) 5-bromo-ortho-cresotamide ##EQU10##
Overall formula: C14 H12 Br NO2
Orange crystals -- melting point: 128°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 5:95.
Rf = 0.48 (U.V. development)
2. N(cyclohexyl) 5-bromo-ortho-cresotamide ##EQU11##
Overall formula: C14 H18 NO2
Beige crystals -- melting point: 150°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 5:95.
Rf = 0.50 (U.V. development).
3. N,N-diethyl, 5-bromo-ortho-cresotamide ##EQU12##
Overall formula: C12 H16 Br NO2
White crystals -- melting point: 77°C.
Silica plate chromatography
Solvent: ethyl acetate/petroleum ether 30:70
Rf : 0.67 (U.V. development).
4. N,N' -diisopropyl 5-bromo-ortho-cresotamide ##EQU13##
Overall formula: C14 H20 Br NO2
Pink crystals -- melting point: 147°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 5:95
Rf : 0.28 (U.V. development)
The O-acetylated derivatives serving as intermediaries in Method B can also be obtained from the amides claimed by treatment with acetic anhydride.
Thus it was possible to synthesize the following derivative:
O-acetyl N,N-diethyl 5-bromo-ortho-cresotamide ##EQU14##
Overall formula: C14 H18 Br NO3
White crystals -- melting point: 90°C.
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 50:50.
Rf : 0.53 (U.V. development).
The applicant was also able to test new derivatives satisfying the general formula, which derivatives are obtained from the etherification of the phenol function.
The preparation and physical-chemical characteristics of a derivative with ether function is given below by way of illustration but not of limitation:
O-allyl 5-bromo ortho-cresotamide ##SPC5##
(R' = NH2, R = CH2 -- CH = CH2, X = Br)
Preparation:
1 mol of 5-bromo ortho-cresotamide is added to a methanolic solution of 1.2 mol of sodium; it dissolves immediately; thereupon 2 mol of allyl chloride are added drop by drop, reflux is effected for several hours, and evaporation to dryness is then effected.
The residue is treated with ether/water, the ether phase is washed with an aqueous solution of 1N soda and then with water until neutral; it is concentrated and crystallized by the addition of petroleum ether.
The white crystals obtained have a melting point of 147°C.
Overall formula: C11 H12 Br NO2
Silica plate chromatography.
Solvent: ethyl acetate/petroleum ether 30:70.
Rf : 0.41 (U.V. development).
Among the O-acyloylated derivatives, the applicant has more particularly studied methyl 2-(α-thenoyloxy) 3-methyl 5-bromo benzoate.
(R = thenoyl Radical R' = OCH3, X = Br)
To 6 g of methyl 5-bromo 2-hydroxy 3-methyl benzoate add 4 g of thenoyl chloride in the presence of 6 g of pyridine; there is obtained, in a yield of 93%, crystals of methyl 2-(α-thenoyloxy) 3-methyl 5-bromo benzoate which are soluble in acetone, chloroform, ether and methanol and insoluble in water, propylene glycol and glycerol.
Melting point: 88°C.
The acute toxicity of these new derivatives is rather low; it has been determined as follows on mice (method of Miller and Tainter):
methyl 5-bromo 2-hydroxy 3-methyl benzoate
Dl50 /per os = about 1.600 mg/kg
5-bromo 2-hydroxy 3-methyl benzamide
Dl50 /per os = about 7.800 mg/kg
5-bromo 2-hydroxy 3-methyl benzamide
Dl50 /i.p. = about 1.500 mg/kg
2-hydroxy 3-methyl benzamide
Dl50 /i.p. = about 700 mg/kg
N (dimethyl N',N'-amino 3'-propyl) 5-bromo-ortho-cresotamide hydrochloride
Dl50 /i.p. = about 316 mg/kg
N (diethyl N',N' -amino 2'-ethyl) 5-bromo-ortho-cresotamide hydrochloride
Dl50 i.p. = about 178 mg/kg
N (morpholino 3'-propyl) 5-bromo-ortho-cresotamide hydrochloride
Dl50 /i.p. = about 237 mg/kg
N (morpholino 2'-ethyl) 5-bromo-ortho-cresotamide hydrochloride
Dl50 /i.p. = 562 mg/kg
N (pyrrolidino 2'-ethyl) 5-bromo-ortho-cresotamide hydrochloride
Dl50 /i.p. = 178 mg/kg
5-chloro ortho-cresotamide
Dl50 /i.p. = 560 mg/kg
methyl 5-chloro ortho-cresotate
Dl50 /i.p. = 178 mg/kg
methyl 5-iodo ortho-cresotate
Dl50 i.p. = 750 mg/kg
methyl 5-nitro ortho-cresotate
Dl50 i.p. = 178 mg/kg
The pharmacological properties of the new derivatives which are the object of the present description have been studied. During their primary pharmacological screening these various substances showed a definite power as depressant of the central nervous system -- sedative, muscular-relaxant and anticonvulsant properties and an anti-pyretic activity. Substantial musculolytic and choleretic properties have also been found. Finally all these derivatives have very definitely potentialized the antalgic power of derivatives such as aspirin, noramidopyrine and even morphine.
a. Technique:
Evaluation of the increase of the duration of the sleep induced by 60 mg/kg of mebubarbital (I.P.) (N = 10 mice).
b. Carrying Out of the Test:
to → oral administration of the compound.
to + 60' → injection of sodium mebubarbital and determination of the periods of narcosis.
c. Results Obtained: (Percentage of increase in the duration of the sleep). COMPOUNDS mg/kg % increase ______________________________________ N (dimethyl N,N'-amino 2'-ethyl) 100 + 78% 5-bromo ortho-cresotamide N (diethyl N,N'-amino 3'-propyl) 50 + 72% 5-bromo ortho-cresotamide 100 + 130% N (dimethyl N,N'-amino 3'-propyl) 5-bromo ortho-cresotamide 100 + 80% N (diethyl N,N'-amino 2'-ethyl) 5-bromo ortho-cresotamide 100 + 102% methyl 2 (α-thenoyloxy) 3-methyl 5-bromo benzoate 100 + 75% N (morpholino 3'-propyl) 5- bromo ortho-cresotamide 100 + 100% N (pyrrolidino 2'-ethyl) 5- bromo orthocresotamide 100 + 100% 5-chloro ortho-cresotamide 50 + 70% 100 + 140% methyl 5-chloro ortho-cresotate 100 + 92% methyl 5-iodo ortho-cresotate 100 + 90% methyl 5-nitro ortho-cresotate 100 + 60% O-acetyl N,N-diethyl 5-bromo ortho-cresotamide 100 + 40% 5-bromo meta-cresotamide 100 + 120% methyl 5-bromo ortho-cresotate 100 + 97% 5-bromo ortho-cresotamide 30 + 29.8% 100 + 132 % 300 + 134 % ______________________________________
The new derivatives which are the object of the present invention also potentialize the sleep induced by chloral hydrate. With respect to anticonvulsive activity (convulsive attacks induced by pentetrazole), the derivatives whose amide function is not substituted have proven to be of the greatest interest.
Technique:
The compound is injected in the mouse interparenterally 30 minutes before the I.V. injection of 75 mg/kg of pentetrazole.
The number of mice showing tonic convulsions is noted and the percentage mortality determined.
The vehicle is an oil solution; a volume of 0.2 mg/20 g of body weight is administered.
______________________________________ |
Results: |
COMPOUNDS mg/kg % protection |
______________________________________ |
Controls (20 mice) 0 0 |
Mephenesine 100 0 |
N-(dimethyl N,N'-amino 2'-ethyl) |
5-bromo ortho-cresotamide |
100 25% |
N (pyrrolidino 2'-ethyl) 5-bromo |
ortho-cresotamide 100 32% |
5-bromo ortho-cresotamide |
100 39.5% |
300 49.3% |
5-chloro orthocresotamide |
100 38% |
200 44% |
Methyl 5-chloro ortho-cresotate |
100 22% |
Methyl 5-iodo ortho-cresotate |
100 20% |
Methyl 5-nitro ortho-cresotate |
100 10% |
5-bromo meta-cresotamide |
100 28% |
______________________________________ |
In view of the homogeneity of this family of new derivatives forming the object of the present patent, the applicant did not deem it necessary, after a prior study of chronic toxicity, to test all the new derivatives in man; however, it selected those which it considered most promising, this manner of procedure, of course, not being of a limitative character.
These derivatives were the subject of clinical tests carried out on volunteers suffering various algias and feverish conditions and, by themselves or associated with other active principles, gave the satisfactory therapeutic results which one had a right to expect.
The formulas of the different drugs containing some of the new derivatives forming the object of this patent are, by way of illustration:
Formula 1 |
Tablets, according to formula: |
5-chloro ortho-cresotamide 300 mg |
Excipients, q.s.p. 1 tablet |
Formula 2 |
Tablets, according to formula: |
5-chloro ortho-cresotamide 150 mg |
Aspirin 350 mg |
Excipients, q.s.p. 1 tablet |
Formula 3 |
Suppositories, according to formula: |
N (morpholino 2'-ethyl) 5-bromo ortho- |
cresotamide hydrochloride 200 mg |
Promethazine 1 mg |
Excipient, q.s.p. 1 suppository |
Formula 4 |
Injectable ampoules (intramuscular), |
according to the formula |
5-bromo meta-cresotamide 100 mg |
Neutralized oil excipient, q.s.p. |
5 ml |
Formula 5 |
Tablets, according to formula |
0-allyl 5-bromo ortho-cresotamide |
150 mg |
Excipient, q.s.p. 1 tablet |
Formula 6 |
Tablets, according to formula |
5-bromo 2-hydroxy 3-methyl benzamide |
250 mg |
Excipients, q.s.p. 1 tablet |
Formula 7 |
Tablets, according to formula |
5-bromo 2-hydroxy 3-methyl benzamide |
150 mg |
Acetyl salicylic acid 350 mg |
Excipients, q.s.p. 1 tablet |
Formula 8 |
Suppositories, according to formula |
5-bromo 2-hydroxy 3-methyl benzamide |
125, 250 and |
500 mg |
Excipients, q.s.p., 1 suppository, "infants," children, |
"adults" |
The present invention also relates to the pharmaceutical forms which can be administered by mouth, rectally, parenterally and locally in which there are associated with the active principles described in the present invention also other active principles which can usefully supplement the therapeutic properties of the new derivatives. An enumeration of these active principles which are widely known and used in therapy could only be limitative.
Cousse, Henri, Stenger, M. Antoine, Mouzin, M. Gilbert
Patent | Priority | Assignee | Title |
4060637, | Jun 21 1971 | Pierre Fabre SA | Medicaments having psychotropic properties |
6646162, | Feb 26 1999 | NOVO NORDISK NORTH AMERICA OPERATIONS A S | Compounds and compositions for delivering active agents |
Patent | Priority | Assignee | Title |
2848418, |
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